Singing nuns are raising the roof at the San Diego Civic Theatre this week in the clichéd but surprisingly funny and well-produced musical “Sister Act.”

Adapted for the stage in 2009 from the 1992 film starring Whoopi Goldberg, “Sister Act” overcomes a corny script with dazzling production values, often-clever lyrics, tongue-in-cheek direction and some standout vocal performances.

“Sister Act” is the story of sassy black Philadelphia nightclub singer Deloris Van Cartier, who is on the run after seeing her hoodlum boyfriend murder a police informant. Smitten cop Eddie helps her hide out in the Queen of Angels convent until she can testify against her ex-beau’s cartoonish goons. There, she upsets the financially struggling order by flouting the Mother Superior’s strict rules, but she turns the nuns’ choir into a citywide sensation by teaching them sexually suggestive pop songs and disco choreography.

The musical version, with score by Alan Menken (of “Little Mermaid” fame) and book by Cheri and Bill Steinkellner with Douglas Carter Beane, is faithful to the original but it develops a love story between Deloris and Eddie and beefs up many of the secondary roles. It has also been reset in the parody-worthy 1970s, which makes for some hilarious sendups of the decade’s good, bad and ugly music (Barry White, Donna Summer), dance (“Saturday Night Fever”), clothing (bell bottoms and ample chest hair) and hairstyles (afros, blow-dried locks and sideburns).

Director Jerry Zaks salvages some of the score’s flimsiest songs with amusing performances and visual gags. And Glenn Slater’s irreverent song lyrics are mostly a hoot (but “It’s Good To Be a Nun” strains too hard into “Book of Mormon” territory).

Klara Zieglerova’s big, glittery scenic design (except for some dreary cathedral drop curtains) is physically impressive and the show’s frantic pacing keeps the energy high. Menken’s score is filled with big-finish solos and high-volume harmonized ensembles that keep the show humming, even when the clunky script hits some potholes.

For the musical, the role of Deloris has been sanitized and sweetened to the point that it strains credulity. Fortunately, Alysha Deslorieux (the understudy, who went on for star Ta’Rea Campbell Wednesday night) is a powerhouse singer with charm and pluck, and she brings some dimension and grit to the role.

Hollis Resnik is more believable as a world-weary Mother Superior. Lael Van Keuren deserves her own show as the shy postulant with the amazing pipes, Sister Mary Robert. As Curtis, Kingsley Leggs is a smooth criminal with solid R&B credentials. As Eddie, E. Clayton Cornelious’s endearing awkwardness saves his character’s ho-hum solos. And Florrie Bagel and Diane J. Findlay amuse as sisters Mary Patrick (the giggly one) and Mary Lazarus (the ancient one who raps), respectively.

“Sister Act” is a hardworking crowd-pleaser that is determined to entertain, despite an often less-than-inspiring script. And while its message is essentially faith-based, it’s not afraid to poke some PG-13-rated fun at the Catholic Church. Its sermon of sisterly love is well worth a listen.